9 research outputs found
Catalytic combustion of sulphur-containing methane lean emissions in a reverse-flow reactor with integrated adsorption
No full textThis work was supported by the Asturian Government (GRUPIN14-078). The author Chiara Urbani acknowledges financial support from the Erasmus program (University of Oviedo - University of Padova
Scuola 2.0: Come insegnare a scrivere testi. Indicazioni per la scuola secondaria di primo grado e per il biennio
No full text
Colloidal TiO2 modified CVD graphene based Hybrid for Electroanalytical Sensing
No full textAn UV photoactive hybrid material, based on graphene film grown by chemical vapor deposition (CVD) and decorated with a closely packed multilayer nanostructured layer of 1-pyrene butyric acid (PBA) coated TiO2 nanocrystals (NCs), has been fabricated by a facile solution-based procedure, for the electrochemical detection of analytes of medical and pharmaceutical interest. A comprehensive investigation of the structural, morphological, spectroscopic, electrical and (photo)electrochemical properties of the hybrid material, as well as of the sensitivity of the composite to selected model analytes upon integration in an electrochemical sensor, are reported.
Motivation and results
Graphene (G) is an extraordinary structural material for sensors, due its excellent electrical conductivity, high surface area and mechanical strength. [1] Its potential application in sensors can be further extended by a further functionalization with organic and inorganic materials. Indeed, the reactivity of graphene, as a two-dimensional platform, opens the venue to a large variety of strategies of hybridization, including molecular decoration approaches with other nanostructured compounds, finally resulting in novel functional composites, that improve the pristine properties and exhibit specific molecular recognition capabilities. Colloidal nanocrystals (NCs), prepared by using solutionbased colloidal chemistry routes, are particularly suited for the chemical decoration of graphene and hence for achieving an effective combination of the original size- and shape-dependent properties of the nano-objects with the unique functionalities of graphene. [2] Here, a solution-based procedure [3] has been implemented, for manufacturing a UV photoactive hybrid material, based on CVD graphene films decorated with UV-light absorbing 1-pyrene butyric acid (PBA) surface coated TiO2 NCs. The hybrid was prepared by exposing the CVD graphene film to a solution of PBA-capped TiO2 NCs, obtained by a ligand exchange procedure, onto pre-synthesized organic-capped NCs (Figure 1 A). The pyrene molecules can anchor the NCs to graphene by π-π stacking interactions, still preserving their aromatic character, while concomitantly interligand π-π forces allow the NC assembling in a highly interconnected nanostructured multilayer coating (Figure 1 B), with retention of the NC geometry and composition. The functional properties of the obtained hybrid have been demonstrated by electrical and (photo)electrochemical investigation and by testing its detection capability towards analytes of medical and pharmaceutical interest in an electrochemical sensor. The results show that the hybrid exhibits higher electrical conductivity, electroactivity (Figure 1 C) and a photoelectric response than bare graphene, preserving concomitantly its high charge mobility and structural properties, and results sensitive to the investigated analytes.
Word count: 392 words
References
[1] K. S. Novoselov et al. (2012): A roadmap for graphene. Nature 490, 192-200
[2] M. L. Curri et al. (2010) Emerging methods for fabricating functional structures by patterning and
assembling engineered nanocrystals. Phys. Chem. Chem. Phys. 12, 11197-11207
[3] C. Ingrosso et al. (2015) Photoactive hybrid material based on pyrene functionalized PbS nanocrystals
decorating CVD monolayer graphene. ACS Appl. Mater. & Interfaces 7, 4151-4159
Corresponding author: Chiara Ingrosso, CNR-IPCF, Sez. Bari, c/o Dip. di Chimica, Università di
Bari, Bari, Italy. Tel:(+39)0805442027, fax: (+39)0805442128, [email protected]
fluoride release from bonding sistems:long term study
No full textPaper #102496
Fluoride release from bonding sistems: long term study
M.G. GANDOLFI1, S. ZANNA1, C. PRATI2, C. BARONI2, and R. MONGIORGI1, 1Center of Biomineralogy, Crystallography and Biomaterials, University of Bologna, Italy, 2Department of Dental Sciences, University of Bologna, Italy
Objectives: The aim of the present study was to evaluate the fluoride releasing from two commercial products (adhesive and composite) using two different analytical techniques. Methods: Ten samples of dental adhesive ONE-UP Bond® F Plus Self-Etching Bonding Agent (Tokuyama Dental Corporation, Tokyo, Japan) and ten samples of composite BEAUTIFIL® Intro set (Shofu Dental Corporation Inc, kyoto, Japan) were prepared by using acrylic moulds with semi-spherical shape (d=10.3 mm, h=4.4 mm). The samples were stored in 55 ml of citric acid solution 0,02 M (pH 2.5) at 37° C. The storage solutions were modified after 7 days, 1,2,3 and 6 months. The obtained solutions were divided into two parts and analyzed for F content using a selective ion-electrode (Orion Research Inc., mod. 940911, Cambride, MA, USA) and a chromatographic column (ICS-90 ion-chromatography system, DIONEX, Sunnyvale, CA, USA). Results: In the table chromatographic and potentiometric analyses respectively. Conclusions: The study shows that the two techniques give quantitative of fluoride releasing data statistically different. The chromatographic technique showed a linear pattern of releasing different from potentiometric technique and the chromatographic technique may consequently be considered more adequate.
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Abstract ID#: 102496
Password: 991502
Submitter's or presenter's Email: [email protected]
Program Selection: Dental Materials 6: Polymer-based Materials - Physical Properties and Performance
Topic: DM 6 Systematic Review Abstracts
Consider for Poster Presentation ONLY: Y
The presenter is a Post-graduate student.
Keywords: Dental materials, Chemical, Fluoride, Composites, Biomaterials
First Author
Maria Giovanna Gandolfi, Dr
Center of Biomineralogy, Crystallography and Biomaterials, University of Bologna
Piazza di Porta San Donato 1
Bologna, 40126
Italy
Phone Number: +39 051 2094913
Fax Number: +39 051 2094904
Email: [email protected]
Second Author
Silvano Zanna, Dr
Center of Biomineralogy, Crystallography and Biomaterials, University of Bologna
Piazza di Porta San Donato 1
Bologna, 40126
Italy
Phone Number: +39-51-2094908
Fax Number: +39-51-2094904
Email: [email protected]
Third Author
Carlo Prati, MD
Department of Dental Sciences, University of Bologna
Via San Vitale 59
Bologna, 40125
Italy
Phone Number: +39 051 278024
Fax Number: +39 051 225208
Email: [email protected]
Membership Number: P211245
Fourth Author
Chiara Baroni
Department of Dental Sciences, University of Bologna
Via San Vitale 59
Bologna, 40125
Italy
Phone Number: +39 051 278024
Fax Number: +39 051 225208
Email: [email protected]
Fifth Author
Presenting
Romano Mongiorgi, Ch
Center of Biomineralogy, Crystallography and Biomaterials, University of Bologna
Piazza di Porta San Donato 1
Bologna, 40126
Italy
Phone Number: +39 051 2094915
Fax Number: +39 051 2094904
Email: [email protected]
Membership Number: P19709
